Question

Using java program, create a Username class.

ask user to type username

1)username length have to >1 and <15

2)username can not include any special character (ex.!@##$}{|\....) ,but it also have to type Spanish or other foreign language

3)user can not include any empty space (ex. user name)

all of three error have to print out. and if there is any error contains, have to ask user to input user name again.

for example:

input username: #$%he f

username can't include any special character

username can't have any empty space

input username: (ask user to input again if there is errors)

Answer 1

Dear student the here is the java code and the output is below the code name the java file as Username.java

Username.java

import java.util.Scanner;

public class Username {

   public static void main(String[] args) {
       // TODO Auto-generated method stub

       Scanner sc=new Scanner(System.in);
       boolean flag=false;
       String uname="";
       do {
       System.out.println("Enter the username");
      
       uname=sc.nextLine();
      
       for(int i=0;i<uname.length();i++)
       {
           if(uname.length()<=1 || uname.length()>=15)
           {
               flag=true;
               System.out.println("The length should be > 1 and <15");
              
               break;
           }
           else if(Character.isSpace(uname.charAt(i)))
           {
               flag=true;
               System.out.println("the username doesnot contain spaces");
              
               break;
           }
          
           else if(!(Character.isLetter(uname.charAt(i)) || Character.isDigit(uname.charAt(i))))
           {
               flag=true;
               System.out.println("the username doesnot contain specail characters");
                  break;
           }
           else {
               flag=false;
           }
          
       }
      
       }while(flag);
      
            System.out.println("The username is "+uname);
   }

}

output:

Enter the username
Bhargavramasitarama
The length should be > 1 and <15
Enter the username
Bhargav@
the username doesnot contain specail characters
Enter the username
Bhargav rama
the username doesnot contain spaces
Enter the username
Bhargav
The username is Bhargav